Abstract
The surface modification and adhesive bonding of a unidirectional GFRP Nylon-6,6 thermoplastic composite has been investigated. Wettability studies of plasma-treated specimens showed a significant reduction in the advancing and receding contact angles in water, relative to untreated material. The most effective treatment used oxygen plasma. The increases in wettability observed were determined to be the result of (a) an increase in the concentration of oxygen- and nitrogen-containing functional groups on the surface of the polymer and, (b) removal of fluoropolymer contamination, the source of which was identified as the PTFE mould release agent. This was established by SSIMS analysis. The surface modification resulted in significantly improved adhesion between the composite and an applied toughened epoxy adhesive; a considerable increase in the Mode II critical strain energy release rate, GIIc, was observed following plasma treatment. Specimens treated in an oxygen plasma showed the greatest improvement in GIIc, failing cohesively at a value of 1.6 kJ·m-2 after only 15 seconds exposure. Without plasma treatment the specimens failed in an adhesive mode at very low values of GIIc. Adhesion was further optimised by moulding the GFRP Nylon-6,6 against steel plates instead of PTFE.
Original language | British English |
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Pages (from-to) | 363-373 |
Number of pages | 11 |
Journal | Interface Science |
Volume | 8 |
Issue number | 4 |
DOIs | |
State | Published - Oct 2000 |